Ipd's phenolic intake manifold spacer insulates the intake manifold from the
cylinder head reducing heat conduction that can raise intake air temps. Cooler
air means more timing, and more timing means more torque. We use only proper G10
GRE (Glass Reinforced Epoxy) phenolic material unlike some PRP (Paper
reinforced plastic) which can fatigue and loose shape in a short period of
time. G10 phenolic is mechanically stronger and provides the best in thermal
transfer resistance translating into lower temps and more power.